In gas-insulated buses installed at electric power plants or electric power substations, a current-carrying conductor is disposed inside a metallic container that is filled with an insulating gas, and an insulating support insulatingly-supports the current-carrying conductor from the metallic container.
In a gas-insulated bus disclosed in Patent Literature 1, a cylindrical shield fitting is implanted inside an insulating spacer that serves as an insulating support for electric conductors, and an electric conductor is inserted through the shield fitting so that the electric conductor is insulatingly supported by the insulating spacer. Moreover, on the inner surface of the shield fitting, a groove is formed along the circumferential direction and a guide ring is placed in the groove in an abutting manner with the electric conductor. That makes the electric conductor and the insulating spacer to be slidable with respect to each other.